[petsc-users] BiCGSTAB for general use

[Paul Anton Letnes]

Dear petsc users.

I am attempting to solve a large, dense equation system. I would like to try using the BiCGSTAB algorithm, and specifically, the petsc library, as it is open source and seems to be well supported. I take it petsc is primarily aimed at people solving partial differential equations by 'brute force' type methods. In my case, I would like to either
1) supply my A and b in Ax = b, and have a library solve it (LU factorization from LAPACK works, but it's slow) or
2) supply matrix products A times a vector (this is what is used internally in BiCGSTAB), the right hand side
If necessary, I have a decent idea for a solution guess for the first iteration.

So my questions are:
1) Is it feasible, and reasonably convenient, to use petsc for this purpose?
2) If so, is there a good example/tutorial/pseudocode somewhere online, or on the mailinglist, for my use case? I have been reading the petsc examples, but they are somewhat tough to follow for a complete petsc beginner. Also, they seem to apply primarily to PDE solving.

I am using the Fortran 90/95 language.

Best regards
Paul